As shown for example at page 179 of the book titled "Torque Converters or Transmissions" authored by P. M. Heldt, a conventional known transmission comprises a drive shaft and two axially spaced pinion gears freely rotatable thereon. The shaft space between the pinion gears is splined to receive an internally splined shift collar. Axial displacement of the shift collar from a centered position causes teeth on the collar to mesh with teeth on the selected pinion gear. It is necessary in this type of transmission that the selected pinion gear be brought up to speed before the shift collar teeth engage the pinion gear teeth. This is conventionally accomplished by friction clutch elements floatably carried on the pinion gears. Each one of the clutch elements is keyed to the shift collar so that axial movement of the collar applies a resilient axial force on the selected clutch element; after the clutch element is drivingly engaged with a companion clutch surface on the pinion gear the shift collar continues its axial movement into mesh with the gear.
Under conventional practice the shift collar applies a resilient axial force on its synchronizer clutch element via a series of small spring-urged bars keyed to the drive shaft. Cam surfaces on the shift collar exert axial forces on the spring-urged bars; as the synchronizer clutch is moved axially into engagement with the pinion gear clutch the spring-urged bars deflect radially inwardly toward the shaft axis to permit continued axial motion of the shift collar.
The present invention concerns a redesign of the spring-bar units to prevent inadvertent dislodgment of the bars caused by accumulations of manufacturing tolerances and/or wear on the bar surfaces. The redesigned units are formed as one piece wire spring elements having central V sections and straight end sections extending oppositely from the V extremities into blind holes in the synchronizer clutch elements. The blind holes are of sufficient depth to compensate for tolerance build-ups and/or wear without permitting dislodgment of the spring elements. The spring elements are designed for easy installation into the relatively confined space between two synchronizer clutches. Principal advantages of the design are reduction in number of parts, ease of installation, better assurance against jamming or dislocation of the spring elements, and longer service life for a given amount of wear.
The invention described herein may be manufactured, used, and licensed by or for the Government for governmental purposes without payment to me of any royalty thereon.